(1) Field of the Invention
The present invention relates generally to a method and system to clear mines underwater. More particularly, this invention relates to dropping tag particles across an area of the ocean and deploying an unmanned underwater vehicle to locate and neutralize mines that have a number of tag particles on them.
(2) Description of the Prior Art
Clearing underwater mines is a complicated, costly endeavor. The per-mine-killed cost of a robust system is often much greater than the cost of each mine. This unbalance is unacceptable since mass produced underwater mines could limit a navy""s ability to operate in vast near-shore areas. The state of the art in mine clearance has relied on using sophisticated unmanned underwater vehicles (UUVs) each having a single warhead. The state of the art UUV locates an underwater mine, maneuvers in close proximity to it, and detonates the warhead. The underwater explosion is successful in the neutralization of a single mine if the UUV is positioned correctly. However, there are several shortcomings to this state of the art approach. The use of an underwater explosion precludes any element of stealth in the clearance of a single mine. This can be a major tactical shortcoming of the current methodology. Another is that the effectiveness of this technique relies on very accurate placement of the detonating charge to at least close proximity to the mine. Consequently, attaining this proximity comes at the considerable cost of a complex targeting system, complex vehicle control systems, and a complex vehicle to house such systems.
Furthermore, the contemporary UUV is often guided by communication links to a surface or underwater platform and requires significant involvement of crew resources to manage the launching, targeting and recovery of the UUV. The time to clear a well-mined area can be excessive and during the mine clearing operation, the naval assets managing and in support of the task may be easily targeted. The fact that simple floating mines may be mass-produced a very low cost produces yet another severe obstacle for an expensive system that can clear only a single mine. The problems associated with targeting mines in shallow water are also a concern, for examples, poor acoustics and water clarity limit traditional targeting systems.
In addition to the existing systems that incorporate at least one UUV in some navies, other devices such as that disclosed in U.S. Pat. No. 6,032,567 have been documented. In an operational sense they too have similar shortcomings regarding targeting and destruction of underwater mines. An additional problem these devices share is their limited effectiveness due to rapid dissipation of explosions or projectiles in an underwater environment.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for a method and apparatus to tag, locate, identify, and neutralize mines.
The first object of the invention is to provide a means to identify underwater mines.
Another object is to provide a method and apparatus to position a vehicle in proximity to an underwater mine.
Another object is to provide a method and apparatus to target an underwater mine.
Another object is to provide means to target an underwater mine in an unfavorable acoustic or visual environment.
Another object is to provide a robust means to destroy underwater mines.
Another object of the invention is to provide a system having the capability to neutralize several underwater mines with a single system during a single mission.
Another object of the invention is to provide a method and apparatus to tag and target mines quickly over a wide area.
Another object is to provide a method and apparatus to tag a plurality of mines from a single airborne platform.
Another object is to provide a method and apparatus to tag mines in a covert fashion.
Another object is to provide a method and apparatus is to tag mines for a finite duration of time.
Another object of the invention is to provide a method and apparatus to quickly identify tagged underwater mines.
Another object of the invention is to provide a method and apparatus for the rapid destruction of tagged mines.
Another object is to provide a method and apparatus to destroy a number of mines in a covert fashion by a single UUV platform.
Another object is to provide a cost effective means to destroy mines from long range.
Another object of the invention is to provide a mine clearance platform that may operate in its own self-defense.
Another object of the invention is to provide a method and apparatus to destroy underwater mines located at different depths in the water.
Another object is to provide a mine clearance system that may operate autonomously or with operator control.
Another object is to provide means to identify more mines than existing systems do.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.
Accordingly, the present invention is a method and apparatus to clear mines underwater. Tag particles are dropped from an aircraft over a wide area of the ocean to sink and stick on submerged mines. An unmanned underwater vehicle (UUV) platform locates and neutralizes mines that have tag particles on them. The platform has an elongate cylindrical-shaped pressure hull that could be launched from a torpedo tube, for example. The tag particles each contain a gas volume dimensioned to resonate with impinging acoustic energy and create reflected portions of the impinging acoustic energy from a targeted mine. The UUV platform has a sonar system provided with at least one transducer to project the acoustic energy through the ambient water. At least one hydrophone transducer in the sonar system receives the reflected portions of the projected acoustic energy to locate a targeted mine to enable its destruction by high-energy supercavitating projectiles fired from the UUV platform. All tag particles dissolve after a period of time to provide no discernable traces of a mine hunting operation.